"Flexible" or "floppy" disks are frequently used as a magnetic storage medium because of their portability and low cost. These disks are called "floppy" because they tend to sag away from their center when not otherwise supported. The space between a magnetic disk and the transducer is critical for proper non-contact data recording and pick-up. It has been common practice in the art to flatten and stabilize the floppy disk during the read/write operation by rotating the disk at high speeds in close juxtaposition to a fixed, flat plate sometimes called a "Bernoulli" plate. In this way, an air bearing is formed between the plate and disk such that the gap between the media surface and the plate is held constant. The thin layer of air between the disk and the plate tends to rotate with the disk and to be thrown outwardly by centrifugal force. This creates a vacuum between the plate and the disk which tends to pull the disk close to the plate and cause it to behave in a substantially rigid manner. This magnetic disk behaving in a substantial rigid manner is then rotated in juxtaposition to magnetic read/write heads disposed very closely to the disk so that the heads "fly" on an air bearing in very close proximity to the disk. This has the advantage of allowing high data density, but without the expense associated with rigid magnetic disks.
It is desirable to somehow texturize or break up the surface of the Bernoulli plates, so that the magnetic media will not cling to the surface, or "ring", as with a perfectly smooth plate. Several methods of texturing the surface have previously been disclosed. One such method provides a Bernoulli plate which is prepared by coining the surface of the disk at numerous locations with a sharply pointed tool. The eruptions that are formed as a result of the coining process are then smoothed by electroplating the plate with a suitable material. This provides a smooth surface on the plate as well as a hard, wear-resistant coating. However, this process is time consuming and expensive, and does not result in significantly higher speeds.
A problem associated with the use of the Bernoulli plate by itself is that the spinning media is sucked down to the Bernoulli plate at higher speeds. This leads to a stopping or hub skipping of the spinning media as well as an unstable servo track which results in media failure. It is also desired to spin the flexible media at higher speeds because spinning the media at higher speeds produces more servo writing media, which in turn allows for an increase output without the investment of additional capital equipment. However, a problem associated with these desired higher speeds is that at higher speeds the spinning media become unstable resulting in unstable servo tracks, signal loss, and media failure.
For the foregoing reasons, there is a need for changing the Bernoulli surface so that the magnetic media can be spun at higher rates. There is also a need to stabilizes the spinning media at these higher speeds to prevent any instability or signal loss.